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Review of the 20” DocTelescopes Lasermax II F3.53
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Review of the 20” DocTelescopes Lasermax II F3.53
Preamble
DocTelescopes Lasermax II F3.53
20” Ultracompact Dobsonian Telescope
For years, I enjoyed using my Orion XX14” Dobsonian for visual observations. However, the hefty wooden base made transport challenging, leading me to seek a more manageable yet larger aperture telescope. After extensive research, I settled on the 20” DocTelescopes Lasermax II F3.53, influenced by its ultracompact design and promising performance.
After considering several candidates from the US, Hong Kong, France, and Italy, I decided to try a telescope made by Marco Guidi at DocTelescopes. The photos suggested a well-made, sturdy telescope.
I ordered the telescope in June 2023 with an expected delivery in late October 2023. I almost opted for the 18” but realized the bottleneck was the size and weight of the heaviest component.
Marco offered a range of optics. I chose a set of quartz optics made by Romano Zen in Italy with top reflectivity.
Months after the down payment, I received bad news: a defect was found on the primary mirror after coating. Although it wasn't his responsibility, Marco covered the extra expense and had Zen repolish the mirror. I had to accept the additional wait, canceling VIP tours at the observatory. We reached a gentleman’s agreement where I would wait a few more months in exchange for an upgrade from Onstep to the latest Servocat system with higher precision encoders at no additional charge.
Here is a detailed review of my experience with this telescope over the past six months.
Product Description/Features
The DocTelescopes Lasermax II F3.53 is a 20” ultracompact Dobsonian telescope, designed for ease of transport and setup. The primary component weighs significantly less than the rocker base of my previous Orion XX14g, making it manageable to handle alone. The telescope features quartz optics crafted by Romano Zen in Italy with high reflectivity coating. The structure is made of laser-cut aluminum, ensuring rigidity without adding unnecessary weight.
A standout feature is the optional Servocat system, which I received as a complimentary upgrade. This system includes high-precision encoders for improved tracking performance. The telescope also includes a high-quality Noctua fan for mirror cooling and a 2” lightweight Feather Touch focuser.
Product Performance
The DocTelescope Lasermax II F3.53 excels in several areas:
- Assembly
and Portability:
Despite its size, the telescope is easy to assemble and disassemble,
fitting conveniently into a Tesla Model 3. The primary mirror, although
heavier than expected, can be easily managed due to the well-designed
rocker base.
- Optical
Performance:
The views through this telescope are breathtaking. Observing M13, the Veil
Nebula, and the Omega Nebula with an OIII filter reveals a level of detail
and a 3D effect I had not seen before. The optical quality of the Zen
mirror, although awaiting further testing during planetary season, is
expected to be excellent.
- Structural
Rigidity: The
aluminum structure is impressively rigid, I believe it would be capable of
supporting mirrors down to f3 without compromising stability. This
rigidity is essential for maintaining collimation and overall performance
during critical planetary imaging.
- Ease
of Use: The
telescope’s design facilitates a quick setup time of 17-20 minutes, with
dismounting taking less than 15 minutes. The process becomes routine after
a few uses, with only minor initial challenges in mounting the clutch
system.
Timelapse of the mounting process can be found here: https://youtu.be/vM0TA2kwp-g
- Customer Support: Marco Guidi provided 24/7 support throughout the purchasing and assembly process via WhatsApp. His continuous dedication has ensured that I could take good care of the telescope. Additionally, Bill Conrad's post-sale service on the ServoCAT system was excellent, even from thousands of miles away.
Other Comments
One downside I encountered was that the mirror wasn’t center-marked upon delivery. Although Marco trusts the collimation to hold over time, I found it necessary to center-mark the mirror myself for critical planetary imaging. Another issue was with the lightweight Feather Touch focuser.
The focuser developed an unacceptable play at f3.53. Marco allowed for a free replacement with another focuser of the same brand and model, which mostly resolved the issue. In retrospect, I believe a sturdier focuser would be more appropriate for this telescope, I would not recommend the feather touch lightweight focuser for anything under f4, in my opinion this focuser is overpriced, especially in Europe.
I cannot overemphasize how rigid the DocTelescope’s laser-cut aluminum structure is. It’s a very welcome surprise, and I believe DocTelescopes can reliably hold mirrors down to f3. Marco even offers lighter options with aeronautical-grade aluminum laser- cut structures.
Summary: The DocTelescopes Lasermax II F3.53 offers a remarkable viewing experience with excellent build quality and customization options. Its ease of transport and assembly make it a top choice. This is a complex telescope not recommended for beginners but a delight for advanced amateur astronomers.
Ratings:
- Design: 10/10
- Customization Options: 10/10
- Build Quality: 9/10
- Structure Rigidity: 10/10
- Price/Quality Ratio: 9/10
- Mirror Quality: Pending further testing but expected to be excellent.
Pere Guerra runs Observatori Astronòmic Albanyà, an astronomical observatory that does science outreach and exoplanet research, having discovered 22 exoplanets since 2017. When work ends and hobby time begins, Pere usually stargazes with all kinds of gear.
- scottinash, dawsonian2000, quality guy and 4 others like this
12 Comments
I’ve been very curious about these telescopes and definitely interested. One question I have please. I look at the position of the focuser and it seems placed differently compared to how I have usually seen focusers on Dobsonians. Please understand I’ve never used a Dob in so I’m not coming from a place of experience. So my question is, assuming you’re in the northern hemisphere and if you were looking at a star in the south, would you be pushing the telescope away from you as you manually track it?
Enhorabuena, Pere! Congratulations on your excellent purchase. Many happy sessions!
What a beautiful beast!
You would be pulling in towards you. You are right that most, if not all, mass produced dobs have the focuser on the other side (left). I'm guessing that the purchaser chose to have it on the right side. Some people prefer that.
It is a beautiful build. Does it come with a primary cover and a stray light baffle around the mirror? Does it come also with a secondary baffle again to reduce stray light?
A frame in titanium complete with titanium fasteners would be perfect as from what I can see there is no provision for dissimilar metal corrosion protection.
I wanted to provide a quick update on the mirror quality, this is the best I could do for the time being as imaging at 5 meters focal lenght is challenging, I was slightly out of focus on Saturn, Jupiter looking quite good I believe.
https://flic.kr/p/2qxXWXf
regarding the focuser placement. couldn't you just turn the secondary around 180 degrees to get the focuser on the left side?
It looks like you can do that on this scope no problem. On my truss dob, I could do that too but then my telrad would be in the wrong spot(under the focuser) and the focuser knobs would be on top instead of bottom.
Very nice telescope. I have only see one other.
The photos looked to be a stack of many hundreds of a single frames. Typically, this not a good arbiter of mirror quality. Even SCT's, in good seeing, will produce breath-taking mages of the planets when stacking is used.
Have you star tested the mirror?
Thanks and congratulations on the very nice Dob!
Lovely scope. Much lighter than my 22”
Regarding focuser placement. I remember Rick Singmaster telling me when he delivered my 24” F4.1 Starmaster in 2006 that the focuser is placed on the right side to prevent you from accidentally falling off the ladder. If the focuser moves away when the telescope tracks you can inadvertently lean further away and end up loosing your balance and falling. With the focuser and tube constantly moving towards you the problem is reduced as you must move the ladder.